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United States Patent | 5,089,711 |
Morsell ,   et al. | February 18, 1992 |
A laser plasma X-ray source for use in photolithography is disclosed wherein an electro-optical shutter is used to trim the output pulse from a master oscillator to a desired duration. The pulse is then split into several pieces which travel along various optical delay paths so that the pieces pass sequentially through a laser power amplifier. After amplification, the pieces are reassembled and then focussed at the plasma target. In a first embodiment, polarization and angle coding methods are used to distinguish each pulse piece at it travels along the delay paths. In a second embodiment, polarization coding is replaced by additional angle coding transverse to the plane of the angles of the first embodiment. An expander/reducer lens assembly is used in both embodiments to reduce the angles between the beam paths and allow more beams to fit closely to the laser amplifier gain region.
Inventors: | Morsell; Arthur L. (Del Mar, CA); Shields; Henry (San Diego, CA) |
Assignee: | California Jamar, Incorporated (San Diego, CA) |
Appl. No.: | 627210 |
Filed: | December 13, 1990 |
Current U.S. Class: | 250/492.3; 250/493.1 |
Intern'l Class: | G03B 041/16 |
Field of Search: | 372/5 250/492.21,493 |
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